Cancer treatment often includes implanting radioactive material such as iodine.sup.125 or palladium.sup.103 seeds into the area of the patient's body to be treated and thereafter subjecting the body to radiation. A seed applicator is used to implant the seeds at spaced locations in the patient's body.
Prior art seed applicators enable seeds to be implanted at fixed spaced-apart locations in the patient's body. However, it has been found to be clinically advantageous to place seeds in a variety of spacing arrangements not easily possible using the prior art applicators.
Prior art applicators include removable magazines that can be preloaded with seeds. There is a need for a mechanism to ensure that the magazines are properly installed in the applicator. Incorrectly installed magazines have been known to fall out of the applicator during use.